Enclosed track overhead cable conveyors

ABSTRACT

The present invention relates to an overhead trolley conveyor of the enclosed track type and in which the trolleys are interconnected by a continuous cable which requires that the cable must pass through each trolley instead of around the trolleys because there is insufficient space within the enclosed track for the cable to bypass any trolley.

United States Patent Inventor John M. Leach P.0. Box 341, Port Jefferson, N.Y. 11777 Appl. No. 17,428 Filed Mar. 9, 1970 Patented Dec. 14, 1971 ENCLOSED TRACK OVERHEAD CABLE CONVEYORS 9 Claims, 4 Drawing Figs.

US. Cl 198/177 R Int. Cl 865g 17/20 Field of Search 198/ l 89.

168, 177; l04/173,94; l05/l55 [56] References Cited UNITED STATES PATENTS 1,377,800 5/1921 Brown 198/177 UX 3,103,896 9/1963 Febley et al. 198/177 X Primary Examiner- Richard E. Aegerter Asrislam Examiner- Douglas D. Watts ABSTRACT: The present invention relates to an overhead trolley conveyor of the enclosed track type and in which the trolleys are interconnected by a continuous cable which requires that the cable must pass through each trolley instead of around the trolleys because there is insufficient space within the enclosed track for the cable to bypass any trolley.

ENCLOSED TRACK OVERHEAD CABLE CONVEYORS BACKGROUND OF THE INVENTION In general overhead conveyors have been divided into open track and closed track types. The open track types have consisted of trolleys carried on I-beams or T-bar tracks and connected together by chains or cables. Thus the tracks have been open and traction wheels or rollers have been required at the turns to guide the chains or cables around the turns.

The closed track types have been enclosed substantially completely in boxlike tracks usually formed from sheet metal and the trolleys have consisted of frames or bodies provided with vertical wheels which vertically support the trolleys and all loads hung from them and alternated with frames or bodies provided with horizontal wheels which guide the trolleys around horizontal turns so that no wheels or rollers are required at turns. The two types of trolleys have generally been directly linked together instead of being interconnected by any flexible element.

The closed track conveyors have been generally more cosmetic in appearance and have provided more protection from any part or dress of a person becoming entangled in the moving trolleys.

The open track types of overhead conveyor have generally been more economical to fabricate because trolley spacing along the chain or cable can be varied to accommodate the size of the load carried instead of being solidly interconnected along the entire length of the conveyor.

SUMMARY OF THE INVENTION The present invention combines the desirable features of both the enclosed type track and open track overhead conveyors. To this end the track is an enclosed type but instead of being linked directly together the vertical and horizontal wheel trolleys are combined into one trolley and the combined trolleys are interconnected by a cable and can thus be spaced apart as required by the sizes of the work loads instead of being solidly connected directly together over the entire length of the conveyor. In this way the number of trolleys required is very frequently reduced and wheel or rollers turns are completely eliminated so that great economies are effected and an attractive appearance and safe operation are all obtained from the same conveyor.

This desirable combination of desirable features has not been easy of achievement, however, because of design features peculiar to the two types of conveyors and space limitations present in the enclosed type.

In the open track type of overhead conveyor the chain or cable connecting the trolleys has been positioned just under the track where there has been plenty of room under all conditions of operation. Whereas, on the enclosed track type such a position for a connecting element would cause the element to be much in the way at all times and dangerous and unsightly as well as place a very unbalanced pulling force on the trolleys which would cause rough running and rapid wear.

The functions of the trolleys during operation of the closed track type of overhead conveyor leave no room over, under or on either side of a trolley. This is because the clearances between the wheels and the four walls of the track is of necessity low because all four of the walls serve as guide tracks for the trolley wheels at some time in the normal operation of the conveyor. The bottom wall guides the vertical wheels on straight horizontal runs and at down turns. The top wall guides the vertical wheels on up turns and one or the other of the sidewalls guides the horizontal wheels on horizontal turns. Furthermore, the connecting element must pull in the geometrical center of the trolleys and in the plane of the axes of the vertical wheels as well as in the exact horizontal central plane of the horizontal wheels in order to exert a balanced pulling force on each trolley.

This leaves but one centrally located essential position for the cable or chain which leaves no room for the cable or chain to pass the trolleys because of interference created by the trolley frames or bodies, the wheel axles and in some cases the wheels themselves. Also, there is much to be gained in the case of a cable to use a continuous cable instead of using short individual lengths of cable to connect successive trolleys together. This is because the cable in continuous length wears better, maintains more accurate spacing between the trolleys and is much more economical.

It was found to be impractical when using a cable to employ alternate separate trolleys, one trolley with vertical wheels and the next trolley with horizontal wheels because the cable would twist and let the two types of trolleys relatively rotate about the axis of the cable and seriously interfere with proper traction of both sets of wheels, particularly on turns. Also, the vertical wheel trolleys would pull in tight against the vertical walls of the track on turns and cause excessive chain pull.

It was found necessary, therefore, to combine the vertical and horizontal wheel trolleys into a single trolley to provide stability and eliminate rubbing but this required a stronger and more bulky trolley body and the additional wheels and axles added to the congested space and further interfered with the passage of the continuous cable.

It has been found that by properly spacing and positioning wheels, eliminating straight-through vertical wheel shafts, positioning horizontal wheel shafts off of the central axis of the trolley body, and shaping the trolley body so as to be free of interference with the track sidewalls and still have sufficient bulk to provide the strength required to support the loads and resist the increased forces, a through space can be provided extending from one end of the trolley to the other end through which a continuous cable can be passed and within which the cable can be anchored to the trolley body so as to provide the smooth and balanced pull required as explained above and still have a trolley which can be easily assembled and economically manufactured.

The objects of the present invention are to provide a trolley construction for an enclosed track overhead conveyor which will enable the trolleys to be successively connected together by a continuous flexible element such as a cable or chain and still operate smoothly with very low friction and be capable of economical manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS The now preferred embodiments of the present invention are illustrated in the accompanying drawings, in which:

FIG. I is a top plan view of a conveyor trolley made in accordance with the present invention;

FIG. 2 is a vertical sectional view taken substantially on the plane represented by line 2-2 of FIG. 1 and looking in the direction of the arrows;

FIG. 3 is a side elevational view of the trolley of FIG. 1 and FIG. 4 is a vertical cross-sectional view similar to FIG. 2 but showing a modified form of vertical wheel mounting.

This conveyor invention has been referred to as an overhead type" because they are so known in the industry. It is to be understood, however, that this invention is clearly capable and intended to be used in any location or level desired and inverted when such would be an advantage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The trolleys 10 of the present invention preferably comprise a frame or body member 12 formed in two sections 14 and 16 provided respectively with open centrally positioned superimposed areas 18 and I0 which receive a closely fitted shaft 22 shaped to fit the areas 18 and 20 and provide a stub shaft extending on each side as shown in FIG. 2. Each stub shaft has a vertical wheel 24 mounted thereon and suitably retained in position, for example, as by providing a conical area 46 in the outer end of the bore of each wheel 24 and counterbored area 48 in the end of each stub shaft and by means of a pointed tool expanding the end of the shaft outwardly into the conical area. The wheels 24 would normally be ball bearing wheels and the bore would be in the inner race hub.

The sections 14 and 16 are also provided with superimposed open areas 26 centrally positioned at right angles to the openings 18 and 2t) and which receive a cable 28 which connects the successive trolleys together into an endless chain which is driven in known manner, for example, by a caterpillar-type drive (not shown) the dogs of which contact the body 12 in the area and in the direction shown by the arrows S in FIG. 1.

Other desired flexible elements can be used as an alternate to the cable 28.

The open areas 26 are enlarged as shown at 32 to provide a centrally located socket to receive an anchor for the cable 28 which is preferably in the form of a sleeve/swaged onto or otherwise suitably attached to the cable 28 and which serves to prevent any relative slippage between the cable and the trolleys.

The anchor sleeves 34 can be positioned at desired distances apart along the cable to provide the desired pitch between the trolleys, for example, 6 inches, 9 inches, 12 inches, etc.

The body sections 14 and 16 are provided with four cutout areas 36 as shown, one at each corner, with a thin wall shaped as shown at 52 in FIG. I left remaining as a precaution against the cable ever rubbing against the wheels 38 and also serving as a curved lead on into the body 12 for the cable 28.

Each wheel 38 is mounted on the body 12 by a flat head capscrew 40 which passes down through a suitable opening in the body section 14, passes through a bore in the hub of the wheel 38 and threads into a suitable threaded opening in the body section 16. The capscrews 40 also serve to hold the two body sections 14 and 16 securely fastened together and the shaft 22 and cable 28 in position within the body 12.

The body construction above described is strong, compact and takes up a minimum of room within the small box track so as to eliminate any possibility of rubbing on the track sides.

A modified form of the present invention is shown in FIG. 4 in which instead of extending from side to side of the body the stub shafts 54 extend into the body and terminate in expanded areas such, for example, as the heads 56. The body sections 14 and 16 are again provided with open areas to snugly receive the heads 6 and thus anchor the stub shafts 54 firmly in place in the same manner as when the shaped shaft 22 is used.

A construction of the type shown in FIG. 2 is preferred because the shaft 22 is curved downwardly to provide a passage for the cable but is continuous from side to side of the body and thus serves to strengthen the body crosswise, and also eliminates all cantilever forces acting on the body.

The shaped areas formed by the downwardly curved part of the shaft 22 and the heads 56 serve to also prevent any axial movement of the shafts of which they form parts.

The horizontal wheels 38 are selected of such size as to extend outwardly horizontally sufficiently beyond the outsides of the vertical wheels 24 so that even on the horizontal turns the vertical wheels cannot rub along the vertical sides of the track. In FIG. I an interior vertical convex turn track wall is represented by the line 60 and it can be seen that a substantial space 62 exists between the vertical wheel 24 nearest the wall and the wall 60.

The trolley construction of the present invention is capable of very easy and rapid assembly because the capscrews 40 serve to hold the sections 14 and 16 together, the shaft 22 in position, the cable 28 in position and the wheels 38 in position so that the entire assembly of the trolleys is effected by insertion of capscrews 40.

With the trolley construction of the present invention it is possible to use wheels 38 which are large enough to have hearing balls which are large enough to have adequate load-carrying capacity and still not so large as to unduly extend the overall length of the trolley. Long trolleys increase the minimum load-carrying spacing materially, and increase the minimum possible horizontal turns.

The trolley structure of the present invention is stable and well balanced which enables the complete conve or system formed therefrom to be smooth in operation an free from pulsations even when very lengthy, as well as to have a comparatively low-chain pull; which greatly increases operating life.

The invention having been described, what is claimed is:

1. A conveyor trolley comprising a body element formed in a plurality of sections, means for fastening said sections together, stub shafts projecting from said body element, a wheel mounted on each stub shaft, a curved section carried by and extending laterally from said stub shafts within said body element, and said body element sections being provided with cavities which closely fit said curved section and anchor said stub shafts to said body element when said body element sections are fastened together.

2. A conveyor as specified in claim I further characterized in that said body element has an unobstructed opening therein extending between said sections in a substantially straight line from one end to the other end thereof, a driving cable extending into said opening at one end, through said body element and out the other end thereof, and means to prevent slippage between said cable and said body element.

3. A conveyor trolley as specified in claim 1 further characterized in that other wheels for guidance of said body element are positioned at substantially right angles to said first named wheels, and means for attaching said other wheels to said body element.

4. A conveyor trolley as specified in claim 3 in which the means for fastening said sections together and the means for attaching said other wheels to said body element are one and the same.

5. A conveyor trolley as specified in claim 2 further characterized in that said stub shafts are connected and extend continuously through said body element and are curved in the center to avoid interference with said driving cable.

6. A conveyor trolley as specified in claim 2 further characterized in that other wheels for guidance of said body element are positioned at substantially right angles to said first named wheels, and means for attaching said other wheels to said body element.

7. A conveyor as specified in claim 6 in which the means for fastening said sections together and the means for attaching said other wheels to said body element are one and the same.

8. A conveyor as specified in claim 1 in which said body sections are two in number and are in superimposed relationship.

9. A conveyor trolley comprising a body element formed in two superimposed sections having cavities formed between them, four of said cavities extending inwardly and horizontally from the sides of said body element, a horizontally positioned wheel disposed in each of said four cavities, means simultaneously fastening each of said wheels to said body element and said sections together, a fifth of said cavities extending from the front to the back of said body element, a continuous cable extending through said fifth cavity, means anchoring said cable within said fifth cavity, a sixth cavity extending through said body element from side to side substantially at right angles to said cable and curved around said cable, a continuous shaft having a curved section to avoid interference with said cable and extending stub ends mounted in said sixth cavity, and a vertically positioned wheel mounted on each end of said shaft. 

2. A conveyor as specified in claim 1 further characterized in that said body element has an unobstructed opening therein extending between said sections in a substantially straight line from one end to the other end thereof, a driving cable extending into said opening at one end, through said body element and out the other end thereof, and means to prevent slippage between said cable and said body element.
 3. A conveyor trolley as specified in claim 1 further characterized in that other wheels for guidance of said body element are positioned at substantially right angles to said first named wheels, and means for attaching said other wheels to said body element.
 4. A conveyor trolley as specified in claim 3 in which the means for fastening said sections together and the means for attaching said other wheels to said body element are one and the same.
 5. A conveyor trolley as specified in claim 2 further characterized in that said stub shafts are connected and extend continuously through said body element and are curved in the center to avoid interference with said driving cable.
 6. A conveyor trolley as specified in claim 2 further characterized in that other wheels for guidance of said body element are positioned at substantially right angles to said first named wheels, and means for attaching said other wheels to said body element.
 7. A conveyor as specified in claim 6 in which the means for fastening said sections together and the means for attaching said other wheels to said body element are one and the same.
 8. A conveyor as specified in claim 1 in which said body sections are two in number and are in superimposed relationship.
 9. A conveyor trolley comprising a body element formed in two superimposed sections having cavities formed between them, four of said cavities extending inwardly and horizontally from the sides of said body element, a horizontally positioned wheel disposed in each of said four cavities, means simultaneously fastening each of said wheels to said body element and said sections together, a fifth of said cavities extending from the front to the back of said body element, a continuous cable extending through said fifth cavity, means anchoring said cable within said fifth cavity, a sixth cavity extending through said body element from side to side Substantially at right angles to said cable and curved around said cable, a continuous shaft having a curved section to avoid interference with said cable and extending stub ends mounted in said sixth cavity, and a vertically positioned wheel mounted on each end of said shaft. 